title: The N-terminal region of the human autophagy protein ATG16L1 contains a domain that folds into a helical structure consistent with formation of a coiled-coil.
abstract: Autophagy is a fundamental cellular process required for organelle degradation and removal of invasive pathogens. Autophagosome formation involves the recruitment of, and interaction between, multiple proteins produced from autophagy-related (ATG) genes. One of the key complexes in autophagosome formation is the ATG12-ATG5-ATG16L1 complex. ATG16L1 functions as a molecular scaffold mediating protein-protein interactions necessary for formation of the autophagosome in response to both classical and pathogen-related autophagy stimuli. The coiled-coil domain of the yeast ortholog, ATG16, exists as a homodimer both in solution and in the crystal form. The yeast and human orthologs show poor sequence identity. Here we have sought to determine the minimal boundaries of the human ATG16L1 coiled-coil domain and ascertain its oligomeric status in solution. Using a range of biochemical and biophysical techniques we show that the secondary structure of the human ATG16L1 coiled-coil has the expected helical composition and that the domain forms a homodimer in solution. We also observe extensive sequence conservation across vertebrates providing strong support for the crucial functional role of the ATG16L1 coiled-coil.
authors.affiliation: Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Rhiannon
authors.initials: R
authors.lastname: Parkhouse
authors.forename: Ima-Obong
authors.initials: IO
authors.lastname: Ebong
authors.forename: Carol V
authors.initials: CV
authors.lastname: Robinson
authors.forename: Tom P
authors.initials: TP
authors.lastname: Monie
mesh_terms: D000595:Amino Acid Sequence; D001343:Autophagy / Q000235:genetics*; D000071183:Autophagy-Related Proteins; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics*; D002850:Chromatography, Gel; D002942:Circular Dichroism; D019295:Computational Biology; D017124:Conserved Sequence / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D040461:Gene Components; D006801:Humans; D013058:Mass Spectrometry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D046912:Multiprotein Complexes / Q000235:genetics*; D010588:Phagosomes / Q000235:genetics*; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014461:Ultracentrifugation
chemical_list: C518959:ATG16L1 protein, human; D000071183:Autophagy-Related Proteins; D002352:Carrier Proteins; D046912:Multiprotein Complexes